The Greenhouse - Tips and Tricks

These are the engines of your garden and are as important as rain is to a rainbow. Learn how to get the most of this valuable resource.

They provide your budding beauties with near perfect growing conditions.

This is were the magic happens. If you want to grow your own plants either from cuttings or seed, then a good greenhouse is essential garden kit. Imagine trying to cook a roast without an oven? And that is essentially what they are – ovens. They provide your budding beauties with near perfect growing conditions. Ive learnt a few key bits of information you need to know to get the most out of them.

Size, Type and Cost

Choose one that you wont grow out of! Im on my third one, outgrowing the first two very quickly. As my garden acreage grows, so does the size of my greenhouse. I like the fact that I can walk into it without ducking my head. It gives me six rows of growing space plus plenty of floor space to add the larger of my plants. I bought mine for $150 new on Trademe. Its a powered coated steel frame with polyurethane covering. This is its second season and is already showing wear and tear. I dream of the day when I can afford a fancy pants aluminium frame with glass one. They are surprisingly pricey. If you don't want to take out a second mortgage to get one I have seen second hand ones of varying condition for sale on Trademe. But at least expect to set you back 1K for a half decent one. Brand new ones are even more expensive. If you do fork out your hard earned cash for one, ensure that you can take it with you if you move!

A plant that grows on uneven ground will grow straight up, so if you don't want wonky off kilter growth this point is vital!

Placement and Orientation

Hours of sun is important when considering placement. It needs at least six hours of direct sunlight to be effective. I had originally placed mine at the bottom terrace out of sight (it is not the prettiest thing) but this position was not optimal. So we put it on the top level next to the garage were it gets all day sun. You may want to have it close to were your beds are located. The closer it is the more likely you will use it. To hide its less than model looks, I have placed potted herbs and flowers in front to create a pleasing scene. Flexi bins make a cool low cost potting solution. They wont last forever mind, once they start looking a bit worn they still useful storage in the potting shed. Choose a site that is relatively level. A plant that grows on uneven ground will grow straight up, so if you don't want wonky off kilter growth this point is vital! You also need it placed near to your water source and any other amenities eg. electricity.

Ventilation

It goes without saying it gets hot in there! Ventilation is critical, choose a type that has openings to create a cross breeze. Our mild climate here in Auckland and my sheltered position means that I don't usually need to close mine up in winter. We rarely get frosts but it does get blisteringly hot. I have clocked the temperature in the 30 Degree Celsius range in there! Ventilation is also important for the health of your plants, it helps prevent fungal and mold diseases that thrive in high humidity environments.

Flooring

You will need to consider flooring that is even, drains well, wont rot and prevents weeds popping up. We created a platform building a timber frame and using the crushed shell left over from the path in the country garden. We were able to get a nice flat even surface that drains well. You will get weeds growing in there even with a weed mat underneath. The crushed shell allows you to easily pull them out, roots and all. This was a free flooring solution for us. Putting down a concrete slab would be more money and effort. If you do go this route just ensure you are 100% happy with its location before pouring your concrete!

Another trick is to use unused seed trays on the top shelf to shelter the shelf below.

Create Shade

Inside and outside the greenhouse. I have a row of potted plants and shrubs in front which helps regulate the temperature from the harsh afternoon sun. Utilize the space by creating micro environments inside the greenhouse. I have placed a few larger plants inside creating shady corners. By providing shady areas you create less harsher conditions for sun sensitive plants especially in the middle of summer. Another trick is to use unused seed trays on the top shelf to shelter the shelf below.

Maintenance and Cleaning

Depending on the type of greenhouse you get will determine how much upkeep it will need. Mine needs quite a lot of maintenance! Polyurethane is not the most robust of materials and has seen its fair share of storms. I am having to duck tape it in places. We also duck taped the frame joins for extra strength. Other than that it has stood up to some intense storm weather and survived for now. You can get replacement covers, Ive seen them for around $60 each. An aluminium frame glass type will need a lot less upkeep and last for many years. What ever type you decide on they will need to be cleaned yearly. Mine gets a good wipe down every spring. Fungal and mold spores thrive in greenhouse conditions prohibiting seed germination. You must maintain a clean and sterile environment in there. I've found that a weak bleach solution does the trick. On this point, you should also clean your seed trays and pots between use, they also harbor fungal spores and other nasties you do not want in your greenhouse.

I find that the middle tray is best for seed germination.

Plant Placement

Not all shelves have the exact same growing conditions. In my greenhouse, the top shelf will always be sunnier therefore hotter and the bottom shady and mild. I only put established sun loving plants on the top shelf, they can take the heat and will thrive. The bottom shelf is perfect for shade lovers and cuttings you trying to root. I find that the middle tray is best for seed germination. This is for my specific site and orientation. Watch your plants, see if they thriving or flagging, experiment with locations and get to know each shelf's micro environments to get the best out of your plants. I rearrange my plants monthly as the season changes.

Watering

You will need to water regularly, early mornings are best. This is again to prevent unwanted fungal growth. If you watered in the evenings, the water would not evaporate off the leaves, which are perfect environments for fungal growth. If you did it in the middle of the day, most of that precious moisture would evaporate and your plants could get leaf burn. If you couldn't be bothered to do it yourself or are just time poor, you may want to look at installing an irrigation system.

Check in Regularly

One of my favorite daily tasks is checking my little beauties. Has anything flowered or is one ready to be planted out into the big bad world? This does lead onto the next point, even if you have set up irrigation, you should still check in regularly. Pests and diseases can wreck havoc over night. I almost lost an entire batch of Canna Lily's to a gang of unscrupulous leaf munching caterpillars! Plants infected with fungal or other pests should be removed/dealt with immediately as to not spread the problem to other healthy plants.

Your greenhouse is your most valuable asset, knowing these tips will vastly improve your plant growth success rates. The difference in growth rates compared to plants grown outside never ceases to amaze me. You can get plants to flower earlier, grow stronger and healthier than their outdoor counterparts. They are well worth the initial cost outlay and will transform the way you grow your plants.